A charge `q` is placed at the centre of the cubical vessel (with one face a open) as shown in figure. The flux of the electric field through the complete vessel is

A charge q is placed at the centre of the open end of a cylindrical vessel . The flux of the electric field through the surface of the vessel is

A charge q is placed at the centre of the open end of a cylindrical vessel . The flux of the electric field through the surface of the vessel is

A charge q is placed at the centre of the open end of a cylindrical vessel . The flux of the electric field through the surface of the vessel is

A charge q is plaed at the centre of a cubical box of side with top open. The flux of electric field through the surface of the cubical box is

A charge Q is placed at a distance a/2 above the centre of a horizontal, square surface of edge a as shown in figure. Find the flux of the electric field through the square surface.